Higher fastening screw

ABSTRACT

The present invention pertains to a higher fastening screw comprising a plurality of concavities formed on the threads, which are connected in sequence for being presented as a state of a single helix. Further, the concavities separately located adjacent to the screw head and to the drilling portion are disposed at relative positions for being accurately aligned by an imaginary line. In this manner, the configuration of the concavities would efficiently cut and sever the fibers of the object, so as to achieve a lower screwing resistance for a higher screwing efficiency and prevent the injuries to the operators.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a screw, in particular a higher fastening screw.

2. Description of the Related Art

Referring to FIG. 1, a conventional screw 1 comprises a screw head 10, a shank 11 extending from the head 10 along a shank axis, a drilling portion 13 disposed at the distal end of the shank 11, and a plurality of threads 12 disposed on the shank 11; wherein each of the threads 12 provides with a notch 121 disposed around the outer edge thereof, and a plurality of the notches 121 are assumed to be sequentially joined by an imaginary line, started from an initial notch c located adjacent to the drilling portion 13 to a final notch d located adjacent to the screw head 10, which results in the line being inclined with respect to the shank axis by an angle.

While screwing, the screw 1 is initially drilled into the object through the drilling portion 13 and the threads 12, and further the notches 121 assist to cut the fibers and receive the debris (not shown in the figures). By means of the inclination of the imaginary line and the smaller angle in FIG. 1, the notches 121 solely spread around part of the shank 11 (shown in end view of FIG. 2) and can not thoroughly cut the fibers of the object. Thereafter, the unsevered fibers would be facilely twisted round the shank 11, which increases the screwing resistance and affects the screwing efficiency.

To improve the aforementioned problems, some operators may intend to dispose a plurality of notches 221 on each of the threads 22, as shown in FIG. 3. However, the more notches 221 are defined on the threads 22, the less each dimension of each notch 221 is obtained. The notches 221 with smaller dimensions would not substantially cut and sever the fibers, and which still renders the fibers to be twisted round the shank and accumulated within the object and furthers the object easily to be destroyed. In addition, the configuration of too many notches 221 on the threads 22 would also cause the problem of the injuries to the operators while screwing. Thus, screw 1 and 2 still requires improvement.

SUMMARY OF THE INVENTION

Therefore, the object of the present invention is to provide a screw comprising a plurality of concavities disposed on the threads for being sequentially connected as a state of a single helix, thereby assisting to thoroughly and sequentially sever fibers for reducing the screwing resistance and preventing from hurting the operators.

The screw in accordance with the present invention comprises a screw head, a shank, a drilling portion and a plurality of threads; wherein a plurality of concavities on the threads are sequentially connected to form a state of a single helix around the shank, started from a initial concavity located adjacent to the drilling portion and terminated at a final concavity located adjacent to the head. The initial concavity and the final concavity are positioned at relative places, thereby accurately aligning the above two concavities by an imaginary line. By means of the assistance of the concavities to cut and sever the fibers, the present invention is conducive to increase the screwing efficiency with less screwing resistance and also prevents from damaging the operators.

The advantages of the present invention over the known prior art will become more apparent to those of ordinary skilled in the art upon reading the following descriptions in junction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a conventional screw;

FIG. 2 is an end view showing the screw of FIG. 1;

FIG. 3 is a perspective view showing another conventional screw;

FIG. 4 is a perspective view showing a screw of a first preferred embodiment of the present invention;

FIG. 5 is an end view showing the screw of FIG. 4;

FIG. 6 is a perspective view showing a screw of a second preferred embodiment of the present invention;

FIG. 7 is a schematic view showing the screw of the first preferred embodiment to be screwed into the object; and

FIG. 8 is a schematic view showing a screw of a third preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before the present invention is described in greater detail, it should be noted that the like elements are denoted by the same reference numerals throughout the disclosure.

Referring to FIG. 4, a screw 3 of a first preferred embodiment comprises a screw head 30, a shank 31 longitudinally extending from the screw head 30, a drilling portion 33 disposed on the distal end of the shank 31, opposite to the screw head 30, and a plurality of threads 32 disposed on the shank 31; wherein each of threads 32 consists of a thread bottom 324 joined to the shank 31 and a thread crest 325 outwardly protruded from the shank 31. Further, a concavity 321 is defined by the inward curve of the thread crest 325 to form a bottom wall adjacent to the thread bottom 324 (shown in a second preferred embodiment of FIG. 6). It is adopted in the preferred embodiments of the present invention that the each of the concavities 321 has a thread crest 325 extremely curved toward the thread bottom 324 (shown in FIG. 4), which results in that the concavity 321 has the bottom wall corresponding to the thread bottom 324 and defines two flanks 327 328 converged toward the thread bottom 324. In this manner, the concavity 321 would be presented as a trapezoid contour shown in the figures of the present invention.

Still further, the concavities 321 on the threads 32 are sequentially connected for being arranged as a state of a single helix around the shank 31, started from an initial concavity ts located adjacent to the drilling portion 33 and terminated at a final concavity t located adjacent to the screw head 30. Moreover, the initial concavity s and the final concavity t are disposed at relative positions, whereby the initial concavity s is accurately aligned with the final concavity t by an imaginary line, and the concavities 321 are defined to be overall spread around the shank 31 (shown in end view of FIG. 5).

Referring to FIG. 7, in manipulation, the operators may hold the screw 3 by steadily gripping the shank 31 and the threads 32 and further transfer a force upon the screw head 30, so that the screw 3 is drilled into the object 4 by the drilling portion 33 and the threads 32 responsible for cutting the fibers of the object 4. Simultaneously, by means of the concavities 321 on threads 32 overall spreading around the shank 31, the flanks 327 328 of the concavity 321 thus aid in continuously cutting and severing the fibers of the object 4 and gradually guiding the debris out, so as to prevent the unsevered fibers from being twisted round the shank 31 and causing the destruction of the object 4. Further, the configuration of the concavities 321 connected as a state of a single helix would also improve the problem of the injuries to the operator, for instance of reducing the cases of hurting the operator s hands while gripping the screw 3.

Referring to FIG. 8, a screw 3 of a third preferred embodiment comprises the similar configurations as the first preferred embodiment. Specifically, the concavities 321 are disposed at an interval of one thread 32 between any of the two threads 32 and still connected as a state of a single helix around the shank 31, and which help cutting the fibers for obtaining a lower screwing resistance with a higher screwing speed and enhancing the screwing stability. Also, the fewer amounts of the concavities 321 on threads 32 facilitate to decrease the possibility of the injuries to the operators.

To sum up, the present invention takes advantages of the concavities on the threads overall spreading around the shank, so as to cooperate with threads to sequentially sever the fibers into debris and to prevent the fibers from being twisted round the shank. As a result, the present invention would be conducive to reduce the screwing resistance for a higher screwing efficiency and avoid hurting the operators while screwing.

While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention. 

1. A higher fastening screw comprising: a screw head; a shank longitudinally extending from said screw head; a plurality of threads spirally disposed on said shank; wherein, each of said threads consisting of a thread bottom joined to said shank and a thread crest outwardly protruded from said shank; and a drilling portion disposed on a distal end of said shank, opposite to said screw head; wherein a concavity being formed by an inward curve of said thread crest; a plurality of said concavities on said threads sequentially connected for being arranged as a state of a single helix around said shank, started from an initial concavity located adjacent to said drilling portion and terminated at a final concavity located adjacent to said screw head; said initial concavity and said final concavity being disposed at relative positions, whereby said initial concavity being exactly aligned with said final concavity by an imaginary line.
 2. The screw as claimed in claim 1, wherein each of said concavities is formed by said thread crest extremely curved toward said thread bottom, thereby defining two flanks converged toward said thread bottom.
 3. The screw as claimed in claim 1, wherein said concavities are disposed at an interval of one thread between any of said two threads. 